This invention relates generally to flow control valves that are used to lower the pressure of fluid flowing therethrough. More particularly, but not by way of limitation, this invention relates to an improved flow control valve having a multiplicity of curvilinear flow paths through the valve that also includes a plurality of orifices located in each flow path.
U.S. Pat. No. 4,004,613 issued to R. M. Purton and R. B. Maddocks on Jan. 25, 1977, describes a valve that is used for similar purposes. However, the orifice assembly of that valve is entirely different than that of the present invention. In that valve, a series of orifice plates alternate with a plurality of spacer plates, but the orifice plates include a series of vertically disposed lands and a plurality of vertically oriented holes drilled in the orifice plates, while the spacer plates are imperforate.
Another somewhat similar valve is manufactured by Copes-Vulcan, Inc. Their valve is designated as the "Hush II Trim". The valve includes a plurality of cylindrical mmbers that make up the orifice assembly for the valve. The cylindrical members are concentrically arranged and each is provided with a plurality of orifices that are aligned to provide flow from the inlet to the outlet through the orifice assembly.
Both of the foregoing valves operate successfully, but the present valve provides a much longer flow path through the valve with many orifices provided for reducing the pressure over greater period of flow time. Thus, the valve functions more efficiently and reduces the noise level as the pressure is reduced. Also, it should be apparent from viewing the drawing of this application as compared to the prior art mentioned above, that the orifice discs and spacer discs can be manufactured much less expensively and by much simpler manufacturing techniques.